1. Field of the Invention
The invention pertains to a windshield that includes a transparent electrically conducting layer, the windshield comprising at least one part of an enclosure within which an antenna for receiving or transmitting microwave radiation is located. The windshield can be an automobile windshield covered by a layer which reflects infrared radiation.
2. Description of the Related Art
Windshields which are provided with an electrically conducting layer with low impedance are used as insulating windshields and/or as electrically heated windshields in the construction industry as well as in the automobile industry. With respect to automobiles, this type of windshield, combined with a casing made of metal, comprises a Faraday cage which isolates the interior of the vehicle from electromagnetic fields: in the construction industry, the use of windows covered by an electrically conducting layer also allows one to electrically isolate rooms when equipping the other walls in an adequate manner. This kind of insulation can also guarantee the protection of sensitive installations such as control consoles against disturbances caused by powerful radio transmitters or radar equipment.
Such electrical insulation, which can be extended to windshields, prevents transmission of electromagnetic radiation in the microwave range. It follows that one cannot use a portable telephone in a vehicle equipped with this type of window. This presents considerable problems if one wishes to install vehicle research and positioning systems, remote control, identification and remote toll devices, or if the transmitter or receiver is located with the antenna inside the vehicle.